/*
 * $Id: FacesInterceptor.java 651946 2008-04-27 13:41:38Z apetrelli $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package haaproject.webwork.jsf;

import javax.faces.context.FacesContext;

import com.opensymphony.xwork.ActionContext;
import com.opensymphony.xwork.ActionInvocation;
import com.opensymphony.xwork.interceptor.Interceptor;

/**
 * Translates JSF phases into individual interceptors, and adapts their expected workflow to Action 2
 */
public class FacesInterceptor extends FacesSupport implements Interceptor {

	private static final long serialVersionUID = -5418255964277566516L;

	/**
	 * Not used
	 */
	public void init() {
	}

	/**
	 * Adapts the phase workflow to Action 2
	 * 
	 * @param invocation
	 *            The action invocation
	 * @return The string result code
	 */
	public String intercept(ActionInvocation invocation) throws Exception {

		if (isFacesEnabled(invocation.getInvocationContext())) {
			FacesContext context = FacesContext.getCurrentInstance();

			if (context.getRenderResponse()) {
				return invocation.invoke();
			} else {

				String viewId = invocation.getProxy().getNamespace() + '/' + invocation.getProxy().getActionName();
				executePhase(viewId, context);

				if (context.getResponseComplete()) {
					// Abort the chain as the result is done
					return null;
				} else {
					if (invocation.getResultCode() != null) {
						return invocation.getResultCode();
					} else {
						return invocation.invoke();
					}
				}
			}
		} else {
			return invocation.invoke();
		}
	}

	/**
	 * Executes the specific phase. The phase id is constructed as a composite of the namespace and action name.
	 * 
	 * @param viewId
	 *            The view id
	 * @param facesContext
	 *            The current faces context
	 * @return True if the next phases should be skipped
	 */
	protected boolean executePhase(String viewId, FacesContext facesContext) {
		return false;
	}

	/**
	 * Not used
	 */
	public void destroy() {
	}

	/**
	 * Determines whether to process this request with the JSF phases
	 * 
	 * @param ctx
	 *            The current action context
	 * @return True if it is a faces-enabled request
	 */
	protected boolean isFacesEnabled(ActionContext ctx) {
		return ctx.get(FACES_ENABLED) != null;
	}

}
